Polycrystalline diamond spherical sliding bearing and drilling tool

Abstract

The present invention relates to the technical field of bearings, and particularly to a polycrystalline diamond spherical sliding bearing and a drilling tool. The polycrystalline diamond spherical sliding bearing comprises a bearing bush and a bearing housing. The bearing bush is provided with a first friction plate, and the bearing housing is provided with a second friction plate. The first friction plate forms a first contact surface, and the second friction plate forms a second contact surface. The first contact surface and the second contact surface are opposite and in sliding contact to form a friction pair. Both the first contact surface and the second contact surface are surfaces of polycrystalline diamond materials. The polycrystalline diamond spherical sliding bearing has the characteristics of small wear, small coefficient of thermal expansion, good thermal conductivity, strong toughness and good impact resistance under high contact pressure. It can meet the requirements of high temperature resistance and corrosion prevention in special application environments, and can work under harsh working conditions such as containing a large amount of high-abrasion solid particles, and can avoid the damage to the bearing material caused by the high heat generated during the start-up or stop of the wear-resistant parts.

Description

[0001] Cross - reference to related applications

[0002] This application claims the priority of a Chinese patent application with the application number 2024100886321, titled "Polycrystalline Diamond Spherical Plain Bearing and Drill Tool", filed on January 22, 2024, which is incorporated herein by reference in its entirety. Technical field

[0003] The present invention relates to the technical field of bearings, and particularly to a polycrystalline diamond spherical plain bearing and a drill tool. Background art

[0004] Existing spherical plain bearings are mainly manufactured by coating hard alloy on the surface of steel. Due to large friction coefficients, relatively poor wear resistance, large thermal expansion coefficients, etc., bearings made of such materials will rapidly wear after working in harsh environments such as high temperature, high load, abrasive wear, and corrosive chemicals for a period of time. They have high failure rates, short service lives, and extremely high maintenance costs, and their service lives cannot meet the application requirements in the described working environments. Summary of the invention

[0005] The present invention provides a polycrystalline diamond spherical plain bearing and a drill tool to solve one of the defects in the prior art. The polycrystalline diamond spherical plain bearing of the present invention has the characteristics of small wear, small thermal expansion coefficient, good thermal conductivity, strong toughness, and good impact resistance under high contact pressure. It can meet the requirements of high temperature resistance and corrosion prevention in special application environments, can work under harsh working conditions such as containing a large amount of high - abrasive solid particles, and can avoid damage to the bearing material caused by high heat generated during the start - up or stop of wear - resistant parts.

[0006] The present invention provides a polycrystalline diamond spherical plain bearing, including a bearing shell and a bearing housing. The bearing shell is provided with a first friction plate, and the bearing housing is provided with a second friction plate. The first friction plate forms a first contact surface, and the second friction plate forms a second contact surface. The first contact surface and the second contact surface are opposite and in sliding contact to form a friction pair, and both the first contact surface and the second contact surface are surfaces of polycrystalline diamond materials.

[0007] According to the polycrystalline diamond spherical plain bearing provided by the present invention, the first contact surface and the second contact surface are in contact and cooperate to form a spherical friction pair.

[0008] According to the polycrystalline diamond spherical plain bearing provided by the present invention, the bearing shell is provided with a first surface, the first friction plate is arranged on the first surface, the bearing housing is provided with a second surface, the second friction plate is arranged on the second surface, and the first surface and the second surface form a spherical fit.

[0009] According to a polycrystalline diamond spherical sliding bearing provided by the present invention, the number of the first friction plates is even, the first friction plates are evenly distributed on the first surface, the number of the second friction plates is odd, and the second friction plates are evenly distributed on the second surface.

[0010] According to a polycrystalline diamond spherical sliding bearing provided by the present invention, the first surface is a spherical surface protruding outwards, and the second surface is a spherical surface recessed inwards.

[0011] According to a polycrystalline diamond spherical sliding bearing provided by the present invention, the first surface is provided with a first groove, the lower part of the first friction plate is embedded in the first groove, and the upper part of the first friction plate protrudes out of the first groove to form the first contact surface, and / or the second surface is provided with a second groove, the lower part of the second friction plate is embedded in the second groove, and the upper part of the second friction plate protrudes out of the second groove to form the second contact surface.

[0012] According to a polycrystalline diamond spherical sliding bearing provided by the present invention, the first friction plates are distributed in multiple layers in a ring shape around the axis of the bearing bush. Among the multiple first friction plates on the first surface, the diameters of the first friction plates gradually decrease from the periphery to the middle of the spherical surface, and / or the second friction plates are distributed in multiple layers in a ring shape around the axis of the bearing housing. Among the multiple second friction plates on the second surface, the diameters of the second friction plates gradually decrease from the periphery to the middle of the spherical surface.

[0013] According to a polycrystalline diamond spherical sliding bearing provided by the present invention, the contact area between the first contact surface and the second contact surface is greater than 90%.

[0014] According to a polycrystalline diamond spherical sliding bearing provided by the present invention, both the first friction plate and the second friction plate include a cemented carbide layer and a polycrystalline diamond layer. The polycrystalline diamond layer is arranged on the end face of the cemented carbide layer, and the polycrystalline diamond layer forms the first contact surface and the second contact surface.

[0015] The present invention also provides a drilling tool, including the polycrystalline diamond spherical sliding bearing as described above.

[0016] The polycrystalline diamond spherical sliding bearing provided by the present invention includes a bearing bush, a bearing housing, and first and second friction plates arranged between the bearing bush and the bearing housing. The bearing bush is a moving ring, the bearing housing is a fixed ring, the fixed ring is arranged outside the moving ring, so that the first friction plate is arranged opposite to the second friction plate. The surface of the first friction plate facing the second friction plate is the first contact surface, and the surface of the second friction plate facing the first friction plate is the second contact surface. The first contact surface and the second contact surface can be in sliding contact to form a friction pair for the sliding contact between the moving ring and the fixed ring.

[0017] The first friction plate and the second friction plate are made of polycrystalline diamond material. Polycrystalline diamond has extremely high hardness, extremely low friction coefficient, high thermal conductivity, corrosion resistance, and high fracture toughness, making the polycrystalline diamond spherical sliding bearing have the characteristics of small wear, small coefficient of thermal expansion, good thermal conductivity, strong toughness, and good impact resistance under high contact pressure. It can meet the requirements of high temperature resistance and corrosion prevention in special application environments, and can work under harsh working conditions such as containing a large amount of high-abrasion solid particles, avoiding damage to the bearing material caused by high heat generated during the start-up or stop of wear-resistant parts. The service life is more than 6-8 times that of spherical sliding bearings with materials such as hard alloy coated on the steel surface. Moreover, polycrystalline diamond also has good self-lubricating performance and can work normally without additional lubrication, reducing the maintenance cost of the equipment.

[0018] For the polycrystalline diamond spherical sliding bearing of the present invention, when the shaft has a certain deflection angle, it can automatically adjust the angle of the tile center line, so that the bearing housing and the bearing tile always maintain good contact, ensuring that the bearing capacity center of the bearing remains unchanged and working normally during the continuous swinging process of the moving ring.

[0019] In addition to the technical problems solved by the present invention, the technical features of the technical solutions constituted, and the advantages brought by these technical features of the technical solutions described above, the other technical features of the present invention and the advantages brought by these technical features will be further described in conjunction with the drawings or understood through the practice of the present invention. Brief Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0021] Figure 1 It is a schematic structural diagram of the polycrystalline diamond spherical sliding bearing provided by the present invention;

[0022] Figure 2 It is a schematic structural diagram of the bearing tile of the polycrystalline diamond spherical sliding bearing provided by the present invention;

[0023] Figure 3 It is a schematic structural diagram of the bearing housing of the polycrystalline diamond spherical sliding bearing provided by the present invention;

[0024] Figure 4 It is a schematic structural diagram of the first friction plate and the second friction plate of the polycrystalline diamond spherical sliding bearing provided by the present invention.

[0025] Reference numerals:

[0026] 100, bearing shell; 110, first surface; 120, first groove;

[0027] 200, bearing housing; 210, second surface; 220, second groove;

[0028] 300, first friction plate; 310, first contact surface;

[0029] 400, second friction plate; 410, second contact surface;

[0030] 500, cemented carbide layer; 600, polycrystalline diamond layer. Detailed implementation manners

[0031] The following further describes the implementation manners of the present invention in detail in conjunction with the drawings and embodiments. The following embodiments are used to illustrate the present invention, but cannot be used to limit the scope of the present invention.

[0032] In the description of the embodiments of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the embodiments of the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0033] In the description of the embodiments of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific situations.

[0034] In the embodiments of the present invention, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the horizontal height of the first feature is less than that of the second feature.

[0035] In addition, in the description of the embodiments of the present invention, unless otherwise specified, the meanings of "a plurality of", "multiple roots", "multiple groups" are two or more, and the meanings of "several", "several roots", "several groups" are one or more.

[0036] In the description of this specification, the descriptions with reference to terms such as "an embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0037] As Figure 1 、 Figure 2 and Figure 3 shown, the polycrystalline diamond spherical sliding bearing provided by the embodiments of the present invention includes a bearing bush 100 and a bearing housing 200. The bearing bush 100 is provided with a first friction plate 300, and the bearing housing 200 is provided with a second friction plate 400. The first friction plate 300 forms a first contact surface 310, and the second friction plate 400 forms a second contact surface 410. The first contact surface 310 and the second contact surface 410 are opposite and in sliding contact to form a friction pair. Both the first contact surface 310 and the second contact surface 410 are surfaces of polycrystalline diamond materials.

[0038] The polycrystalline diamond spherical sliding bearing according to the embodiment of the present invention includes a bearing bush 100, a bearing housing 200, and a first friction plate 300 and a second friction plate 400 disposed between the bearing bush 100 and the bearing housing 200. The bearing bush 100 is a moving ring, and the bearing housing 200 is a stationary ring. The stationary ring is disposed outside the moving ring, so that the first friction plate 300 is disposed opposite to the second friction plate 400. The surface of the first friction plate 300 facing the second friction plate 400 is a first contact surface 310, and the surface of the second friction plate 400 facing the first friction plate 300 is a second contact surface 410. The first contact surface 310 and the second contact surface 410 can be in sliding contact to form a friction pair for the sliding contact between the moving ring and the stationary ring.

[0039] The wear failure of the friction pair is an important factor affecting the spherical sliding bearing. To improve the service life of the spherical sliding bearing, the material selection of the friction pair is particularly crucial. The first friction plate 300 and the second friction plate 400 are made of polycrystalline diamond material. Polycrystalline diamond has extremely high hardness, extremely low friction coefficient, high thermal conductivity, corrosion resistance, and high fracture toughness, making the polycrystalline diamond spherical sliding bearing have the characteristics of small wear, small thermal expansion coefficient, good thermal conductivity, strong toughness, and good impact resistance under high contact pressure. It can meet the requirements of high temperature resistance and corrosion prevention in special application environments and can work under harsh working conditions such as containing a large amount of abrasive solid particles, avoiding damage to the bearing material caused by high heat generated during the start-up or stop of the wear-resistant parts. The service life is more than 6 to 8 times that of the spherical sliding bearing with materials such as hard alloy coated on the steel surface. Moreover, polycrystalline diamond also has good self-lubricating performance and can work normally without additional lubrication, reducing the maintenance cost of the equipment.

[0040] For the polycrystalline diamond spherical sliding bearing of the present invention, when the shaft has a certain deflection angle, it can automatically adjust the angle of the center line of the bearing bush, so that the bearing housing 200 and the bearing bush 100 always maintain good contact, ensuring that the bearing capacity center of the bearing remains unchanged and working normally during the continuous swinging process of the moving ring.

[0041] According to an embodiment provided by the present invention, the first contact surface 310 and the second contact surface 410 are in contact and cooperate to form a spherical friction pair. In this embodiment, the friction pair formed by the first contact surface 310 and the second contact surface 410 is a spherical friction pair, and the spherical diameter is 10 - 500 mm. After the bearing housing 200 and the bearing bush 100 are assembled, when the bearing bush 100 does not generate a swing angle in the axial direction, the first contact surface 310 and the second contact surface 410 of the sphere are completely attached. Increasing the attachment area of the first contact surface 310 and the second contact surface 410 can improve the bearing capacity, thereby further improving the service life of the bearing.

[0042] A spherical plain bearing is a mechanical component used to support and guide a rotating shaft. The spherical bearing shell is also called a self - adapting shell, and its outer surface is spherical. A bearing shell 100 in the shape of a hemispherical body is matched with a bearing housing 200 with an inner spherical surface to form a bearing group that can carry loads and self - align. It can automatically adjust the angle of the center line of the bearing shell, so that the bearing housing 200 and the bearing shell 100 always maintain good contact, ensuring that the bearing capacity center of the bearing remains unchanged.

[0043] In this embodiment, the first contact surface 310 is a spherical surface protruding outward, and the second contact surface 410 is a spherical surface recessed inward. In other embodiments, the first contact surface 310 can also be a spherical surface recessed inward, and the second contact surface 410 can be a spherical surface protruding outward.

[0044] According to an embodiment provided by the present invention, the bearing shell 100 is provided with a first surface 110, the first friction plate 300 is arranged on the first surface 110, the bearing housing 200 is provided with a second surface 210, the second friction plate 400 is arranged on the second surface 210, and the first surface 110 and the second surface 210 form a spherical fit.

[0045] In this embodiment, both the bearing shell 100 and the bearing housing 200 are annular steel bodies with a certain thickness. In the axial direction of the bearing, the first surface 110 and the second surface 210 are opposite between the bearing shell 100 and the bearing housing 200. Therefore, the first friction plate 300 is arranged on the first surface 110, and the second friction plate 400 is arranged on the second surface 210.

[0046] In this embodiment, the first friction plate 300 and the second friction plate 400 with polycrystalline diamond are respectively welded to the first surface 110 of the bearing shell 100 and the second surface 210 of the bearing housing 200 by vacuum welding. Vacuum welding can prevent the molten metal from being polluted by harmful gases such as oxygen and nitrogen, and is also beneficial to the degassing and purification of the weld metal. Welding in a vacuum results in a pure, smooth, and oxidation - free weld. Since there is no air pressure, the welded parts are not easily deformed during welding. Therefore, using vacuum welding can greatly improve the welding quality, making the surface slag - free, gap - free, and without solder paste overflow. After welding, there are no cracks or edge - dropping situations in the first friction plate 300 and the second friction plate 400, and there are no gaps at the joints between the first friction plate 300 and the second friction plate 400 and the bearing shell 100 and the bearing housing 200, and the connection is firm and not easily detached, which can greatly reduce the welding defect rate, reduce material loss, and damage to the welding object.

[0047] In other embodiments, the first friction plate 300 and the second friction plate 400 can also be respectively welded to the first surface 110 of the bearing shell 100 and the second surface 210 of the bearing housing 200 by brazing.

[0048] According to an embodiment provided by the present invention, the number of the first friction plates 300 is even, and the first friction plates 300 are evenly distributed on the first surface 110. The number of the second friction plates 400 is odd, and the second friction plates 400 are evenly distributed on the second surface 210. In this embodiment, a plurality of first friction plates 300 are evenly distributed along the circumferential direction on the first surface 110 of the bearing shell 100, and the plurality of first friction plates 300 are closely arranged. A plurality of second friction plates 400 are evenly distributed along the circumferential direction on the second surface 210 of the bearing seat 200, and the plurality of second friction plates 400 are closely arranged. The number of the first friction plates 300 is even, and the number of the second friction plates 400 is odd, which can ensure that when the bearing shell 100 rotates relative to the bearing seat 200, the first friction plates 300 and the second friction plates 400 always have spherical contact, reduce the generation of heat, and improve the service life of the bearing.

[0049] In this embodiment, the first friction plates 300 and the second friction plates 400 are circular plates with a certain thickness. In other embodiments, the number of the first friction plates 300 and the second friction plates 400 can be set according to actual needs. The number of the first friction plates 300 and the second friction plates 400 is affected by factors such as their own diameters and the circumferences of the first surface 110 and the second surface 210.

[0050] According to an embodiment provided by the present invention, the first surface 110 is a spherical surface protruding outward, and the second surface 210 is a spherical surface recessed inward. In this embodiment, the first surface 110 and the second surface 210 in a relatively arranged relationship are both spherical surfaces, and the curvatures of the two spherical surfaces cooperate with each other. The purpose is to make the surfaces of the bearing shell 100 and the bearing seat 200 fit better, and they can cooperate better when the bearing works. When the bearing shell 100 generates a swing angle within 5° along the axial direction, it can automatically adjust the angle of the center line of the bearing shell 100, so that the bearing seat 200 and the bearing shell 100 always maintain good contact, ensure that the bearing capacity center remains unchanged, make its stability better during rotation and guiding work, and improve its wear resistance and impact resistance.

[0051] In other embodiments, the first surface 110 can also be a spherical surface recessed inward, and the second surface 210 can also be a spherical surface protruding outward.

[0052] According to an embodiment provided by the present invention, the first surface 110 is provided with a first groove 120, the lower part of the first friction plate 300 is embedded in the first groove 120, and the upper part of the first friction plate 300 protrudes from the first groove 120 to form a first contact surface 310. In this embodiment, the first surface 110 of the bearing shell 100 is processed into a surface with the first groove 120. The number of the first grooves 120 is the same as the number of the first friction plates 300, and the first friction plates 300 can be embedded in the first grooves 120 to realize connection with the bearing shell 100.

[0053] The provision of the first groove 120 facilitates the positioning and fixation of the first friction plate 300. Affected by the length of the bearing itself along its axial direction, the thickness of the first friction plate 300 and the second friction plate 400 between the first surface 110 and the second surface 210 is limited. That is, the part of the first friction plate 300 protruding from the first surface 110 is relatively thin. The design of the first groove 120 can also make the first friction plate 300 be manufactured into a part structure with a certain thickness, which is convenient for the processing and manufacturing of the first friction plate 300.

[0054] According to an embodiment provided by the present invention, the second surface 210 is provided with a second groove 220. The lower part of the second friction plate 400 is embedded in the second groove 220, and the upper part of the second friction plate 400 protrudes from the second groove 220 to form a second contact surface 410. In this embodiment, the second surface 210 of the bearing shell 100 is processed into a surface with a second groove 220. The number of the second grooves 220 is the same as the number of the second friction plates 400. The second friction plates 400 can be embedded in the second grooves 220 to connect with the bearing seat 200.

[0055] The provision of the second groove 220 facilitates the positioning and fixation of the second friction plate 400. Affected by the length of the bearing itself along its axial direction, the thickness of the first friction plate 300 and the second friction plate 400 between the first surface 110 and the second surface 210 is limited. That is, the part of the second friction plate 400 protruding from the second surface 210 is relatively thin. The design of the second groove 220 can also make the second friction plate 400 be manufactured into a part structure with a certain thickness, which is convenient for the processing and manufacturing of the second friction plate 400.

[0056] According to an embodiment provided by the present invention, the first friction plate 300 can be installed on the first surface 110 through the first groove 120. At the same time, the second friction plate 400 can be installed on the second surface 210 through the second groove 220.

[0057] According to an embodiment provided by the present invention, the first friction plates 300 are distributed in multiple layers in a ring shape around the axis of the bearing shell 100. Among the multiple layers of the first friction plates 300 on the first surface 110, the diameter of the first friction plates 300 gradually decreases from the periphery to the middle direction of the spherical surface. In this embodiment, the first friction plates 300 are arranged in multiple layers on the first surface 110. Each layer of the first friction plates 300 is formed by a plurality of the first friction plates 300 evenly distributed around the axis of the bearing shell 100. Since the first surface 110 is a convex spherical surface, the edge of the spherical surface is the periphery, and the highest point of the spherical surface is the middle. The arrangement form of the multiple layers of the first friction plates 300 is arranged in sequence from the periphery to the middle direction of the spherical surface, and the diameter of the first friction plates 300 also gradually decreases accordingly.

[0058] In this embodiment, on the convex spherical surface of the first surface 110, the distribution range of each layer of the first friction plates 300 gradually decreases. To adapt to the distribution area and meet the requirement of an even number of the first friction plates 300 on the first surface 110, the diameter of the first friction plates 300 changes regularly. And to ensure that the distribution range of the first friction surface on the bearing shell 100 is sufficient, the first friction plates 300 on adjacent two layers of the first friction plates 300 are arranged at intervals and staggered.

[0059] According to an embodiment provided by the present invention, the second friction plates 400 are distributed in multiple layers in a ring shape around the axis of the bearing housing 200. Among the multiple layers of the second friction plates 400 on the second surface 210, the diameter of the second friction plates 400 gradually decreases from the four circumferences of the spherical surface towards the middle. In this embodiment, the second friction plates 400 are arranged in multiple layers on the second surface 210. Each layer of the second friction plates 400 is formed by a plurality of the second friction plates 400 evenly distributed around the axis of the bearing left. Since the second surface 210 is a concave spherical surface, the edge of the spherical surface is the four circumferences, and the highest point of the spherical surface is the middle. The arrangement form of the multiple layers of the second friction plates 400 is sequentially arranged from the four circumferences of the spherical surface towards the middle direction, and the diameter of the second friction plates 400 also gradually decreases accordingly.

[0060] In this embodiment, on the concave spherical surface of the second surface 210, the distribution range of each layer of the second friction plates 400 gradually decreases. To adapt to the distribution area and meet the requirement of an odd number of the second friction plates 400 on the second surface 210, the diameter of the second friction plates 400 changes regularly. And to ensure that the distribution range of the second friction surface on the bearing shell 100 is sufficient, the second friction plates 400 on adjacent two layers of the second friction plates 400 are arranged at intervals and staggered.

[0061] According to an embodiment provided by the present invention, the first friction plates 300 on the first surface 110 are arranged in multiple layers in a form that the diameter gradually decreases from the four circumferences of the spherical surface towards the middle. At the same time, the second friction plates 400 on the second surface 210 are also arranged in multiple layers in a form that the diameter gradually decreases from the four circumferences of the spherical surface towards the middle.

[0062] According to an embodiment provided by the present invention, the contact area between the first contact surface 310 and the second contact surface 410 is greater than 90%. In this embodiment, the first contact surface 310 and the second contact surface 410 form a spherical friction pair. Through the laser and electro - machining forming processing method, the spherical surface matching degree of the first contact surface 310 and the second contact surface 410 is processed to be within 0.015 mm, ensuring that the contact area between the bearing housing 200 and the bearing shell 100 during the operation of the bearing is above 90%.

[0063] In this embodiment, the first friction plate 300 and the second friction plate 400 are processed into spherical surfaces by using laser and electro - machining forming methods, which improves the machining accuracy and can further improve the wear resistance, impact resistance and service life of the polycrystalline diamond spherical sliding bearing applied to the rotary steerable drilling tool.

[0064] According to an embodiment provided by the present invention, the cross - sectional radius of the bearing tile 100 gradually increases along its axial direction. In this embodiment, the outer side surface of the bearing tile 100 gradually bends inwards and inclines to form an arc surface, so that the whole bearing tile 100 forms a spherical shape. This spherical surface can be used as the first surface 110. The bearing seat 200 cooperates with the bearing tile 100. The inner side surface of the bearing seat 200 gradually bends outwards and inclines to form an outward - expanding surface of the mating arc surface, and this outward - expanding surface can be used as the second surface 210.

[0065] In this embodiment, both the bearing tile 100 and the bearing seat 200 are integral rings. During assembly, the bearing tile 100 can directly insert into the outward - expanding surface of the bearing seat 200 by using its two ends along the axial direction, with one end having a larger radius and the other end having a smaller radius.

[0066] In other embodiments, the bearing seat 200 can be a split - combination ring. During assembly, the bearing seat 200 uses its split form to enclose the outside of the bearing tile 100 by splicing, or the bearing tile 100 can be a split - combination ring. During assembly, the bearing tile 100 uses its split form to enclose the inside of the bearing seat 200 by splicing.

[0067] As Figure 3 shown, according to an embodiment provided by the present invention, both the first friction plate 300 and the second friction plate 400 include a cemented carbide layer 500 and a polycrystalline diamond layer 600. The polycrystalline diamond layer 600 is arranged on the end face of the cemented carbide layer 500, and the polycrystalline diamond layer 600 forms the first contact surface 310 and the second contact surface 410. In this embodiment, both the first friction plate 300 and the second friction plate 400 are polycrystalline diamond composite sheets, which are composed of the polycrystalline diamond layer 600 and the cemented carbide layer 500 by high - temperature and high - pressure sintering. They have both the high hardness, high wear resistance and thermal conductivity of diamond and the strength and impact toughness of cemented carbide. The polycrystalline diamond layer 600 is arranged at one end of the cemented carbide layer 500. The cemented carbide layer 500 can be embedded in the groove as the lower part of the friction plate, and the polycrystalline diamond layer 600 can protrude from the groove as the upper part of the friction plate.

[0068] In this embodiment, the outer diameters of the first friction plate 300 and the second friction plate 400 are φ6 - 25 mm, and the overall thickness is 110 mm. The thickness of the polycrystalline diamond layer 600 is 0.5 - 3 mm. The upper surface chamfer of the polycrystalline diamond layer 600 is at 45 - 60°, and the chamfer size is in the range of 0.2 - 3 mm. The cemented carbide layer 500 serves as the substrate and is located on the lower surface of the polycrystalline diamond layer 600. The lower surface chamfer of the cemented carbide layer 500 is at 45 - 60°, and the chamfer size is in the range of 0.2 - 0.5 mm.

[0069] An embodiment of the present invention further provides a drilling tool, including the polycrystalline diamond spherical sliding bearing as described in the above embodiment.

[0070] The drilling tool of the embodiment of the present invention provides a rotary steerable drilling tool. By using the friction plate formed by polycrystalline diamond composite on the polycrystalline diamond spherical sliding bearing, it is more wear-resistant, more impact-resistant, more high-temperature resistant, and more corrosion-resistant, which can greatly improve the service life of the polycrystalline diamond spherical sliding bearing applied to the rotary steerable drilling tool and improve the reliability of use.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A polycrystalline diamond spherical sliding bearing, characterized in that: It includes a bearing shell and a bearing housing. The bearing shell is provided with a first friction plate, and the bearing housing is provided with a second friction plate. The first friction plate forms a first contact surface, and the second friction plate forms a second contact surface. The first contact surface and the second contact surface are opposite to each other and in sliding contact to form a friction pair. Both the first contact surface and the second contact surface are surfaces of polycrystalline diamond materials. The bearing shell has a first surface, and the first friction plate is arranged on the first surface. The bearing housing has a second surface, and the second friction plate is arranged on the second surface. The first surface and the second surface form a spherical fit. The first friction plates are distributed in multiple layers in a ring shape around the axis of the bearing shell. Among the multiple first friction plates on the first surface, the diameter of the first friction plate gradually decreases from the periphery to the middle of the spherical surface. And / or, the second friction plates are distributed in multiple layers in a ring shape around the axis of the bearing housing. Among the multiple second friction plates on the second surface, the diameter of the second friction plate gradually decreases from the periphery to the middle of the spherical surface. Both the first friction plate and the second friction plate include a cemented carbide layer and a polycrystalline diamond layer. The polycrystalline diamond layer is arranged on the end face of the cemented carbide layer. The polycrystalline diamond layer forms the first contact surface and the second contact surface. The first contact surface and the second contact surface are in contact and cooperate to form a spherical friction pair. The contact area between the first contact surface and the second contact surface is greater than 90%. The first friction plates on adjacent two layers of the first friction plates are arranged at intervals and staggered. The second friction plates on adjacent two layers of the second friction plates are arranged at intervals and staggered. The first friction plate and the second friction plate are respectively welded to the first surface and the second surface by vacuum welding, and the first friction plate and the second friction plate are spherically processed by the methods of laser and electric machining forming.

2. The polycrystalline diamond spherical sliding bearing according to claim 1, characterized in that: The number of the first friction plates is an even number, and the first friction plates are evenly distributed on the first surface. The number of the second friction plates is an odd number, and the second friction plates are evenly distributed on the second surface.

3. The polycrystalline diamond spherical sliding bearing according to claim 1, wherein: The first surface is a spherical surface protruding outwards, and the second surface is a spherical surface recessed inwards.

4. The polycrystalline diamond spherical sliding bearing according to claim 1, wherein: The first surface is provided with a first groove, the lower part of the first friction plate is embedded in the first groove, and the upper part of the first friction plate protrudes out of the first groove to form the first contact surface. And / or, the second surface is provided with a second groove, the lower part of the second friction plate is embedded in the second groove, and the upper part of the second friction plate protrudes out of the second groove to form the second contact surface.

5. The polycrystalline diamond spherical sliding bearing according to claim 1, characterized in that: The cross-sectional radius of the bearing shell gradually increases along its axial direction.

6. A drilling tool, characterized in that: It includes the polycrystalline diamond spherical sliding bearing according to any one of claims 1 to 5.

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